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no_i2p volume option

Hello,

What is the recommended value for the no_i2p option for volumes containing LUNs?

The only description I found was this ...

If this option is on, it disables inode to parent pathname translations on the volume. The default setting is off.

What are the consequences if I set this option to "on"?

Brgds

Nicolas

Re: no_i2p volume option

Greetings,

A while back I ran a bunch of  upgrades from 7.0 -- which 7.1 I believe was the first release with i2p. Initially it consumed a large amount of system resources to complete the initial i2p wafl scan. With some of the nodes, this was not bearable, so it was disabled. I have since enabled many of them, and did not notice any significant improvement after the scan completed.

I have left the option set to on for periods of a month or so without any repurcussions. Ofcourse I was only running NFS (no iSCSI or FC LUNS).

I read the following TR for more information:

http://now.netapp.com/NOW/knowledge/docs/olio/guides/pdfs/tr/tr-3679.pdf

Supposedly i2p helps with the following (from the tr):

• FPolicy services: FPolicy refers to the storage system’s file policy feature, which provides a flexible
way to implement file policies through the use of a specialized off-storage system server. It is an
infrastructure that allows external servers to register certain file system events (for example, file open,
create, remove, rename, and directory create) and to receive callbacks when these events actually
occur on the storage system as a result of a client access. FPolicy events triggered through NFS need
the i2p information to report the complete file path to the FPolicy servers. The i2p information is used to
convert the inode number reported by the NFS client to a complete file path.
• Virus scanning services for UNIX® and NFS clients: External virus scanning servers need a
complete file path to check for virus signatures. The i2p feature supplies this file path by converting the
inode number provided by NFS clients to a file path.
• CIFS ChangeNotify requests: In a multiprotocol environment, the i2p feature allows CIFS change
requests to be posted for files that are being accessed by NFS clients for various NFS file operations. 
• File auditing: Auditing file accesses and other file-related operations requires a complete file path.
Some file operations reference a file by its inode number, so the i2p information is required to translate
the inode number back to the file path and to record the information for audit purposes.
3       Inode To Pathname (i2p) feature of Data ONTAPDATA ONTAP INTERNAL USE
• User-friendly error reporting from within Data ONTAP: Some Data ONTAP error messages
present the complete file path for the file instead of an inode number.
• Efficient Internal operations: Some Data ONTAP internal operations are faster and more efficient
if i2p information is available. 
• Efficient implementation: I2p provides  efficient implementation for some Data ONTAP features. 
o The dump command in Data ONTAP 7.3 completes faster if the i2p information is
available.

Re: no_i2p volume option

Thanks alot. Your answer was really helpful.

Brgds

Nicolas